Mercurial > sdl-ios-xcode
view docs/html/sdlpalette.html @ 2042:3908e1f808e1
Fixed bug #292
I might be on crack here.
It looks like SDL_ConvertMono() in src/audio/SDL_audiocvt.c adds the left and
right channels of a stereo stream together, and clamps the new mono channel if
it would overflow.
Shouldn't it be dividing by 2 to average the two sample points instead of
clamping? Otherwise the mono sample point's volume doubles in the conversion.
This would also make the conversion faster, as it replaces two branches per
sample frame with a bitwise shift.
--ryan.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 24 Sep 2006 15:56:36 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_Palette</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="Video" HREF="video.html"><LINK REL="PREVIOUS" TITLE="SDL_Color" HREF="sdlcolor.html"><LINK REL="NEXT" TITLE="SDL_PixelFormat" HREF="sdlpixelformat.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >SDL Library Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="sdlcolor.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlpixelformat.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLPALETTE" ></A >SDL_Palette</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN3129" ></A ><H2 >Name</H2 >SDL_Palette -- Color palette for 8-bit pixel formats</DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN3132" ></A ><H2 >Structure Definition</H2 ><PRE CLASS="PROGRAMLISTING" >typedef struct{ int ncolors; SDL_Color *colors; } SDL_Palette;</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN3135" ></A ><H2 >Structure Data</H2 ><DIV CLASS="INFORMALTABLE" ><A NAME="AEN3137" ></A ><P ></P ><TABLE BORDER="0" CLASS="CALSTABLE" ><TBODY ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >ncolors</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Number of colors used in this palette</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >colors</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Pointer to <A HREF="sdlcolor.html" ><SPAN CLASS="STRUCTNAME" >SDL_Color</SPAN ></A > structures that make up the palette.</TD ></TR ></TBODY ></TABLE ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN3150" ></A ><H2 >Description</H2 ><P >Each pixel in an 8-bit surface is an index into the <TT CLASS="STRUCTFIELD" ><I >colors</I ></TT > field of the <SPAN CLASS="STRUCTNAME" >SDL_Palette</SPAN > structure store in <A HREF="sdlpixelformat.html" ><SPAN CLASS="STRUCTNAME" >SDL_PixelFormat</SPAN ></A >. A <SPAN CLASS="STRUCTNAME" >SDL_Palette</SPAN > should never need to be created manually. It is automatically created when SDL allocates a <SPAN CLASS="STRUCTNAME" >SDL_PixelFormat</SPAN > for a surface. The colors values of a <A HREF="sdlsurface.html" ><SPAN CLASS="STRUCTNAME" >SDL_Surface</SPAN ></A >s palette can be set with the <A HREF="sdlsetcolors.html" ><TT CLASS="FUNCTION" >SDL_SetColors</TT ></A >.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN3163" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlcolor.html" ><SPAN CLASS="STRUCTNAME" >SDL_Color</SPAN ></A >, <A HREF="sdlsurface.html" ><SPAN CLASS="STRUCTNAME" >SDL_Surface</SPAN ></A >, <A HREF="sdlsetcolors.html" ><TT CLASS="FUNCTION" >SDL_SetColors</TT ></A > <A HREF="sdlsetpalette.html" ><TT CLASS="FUNCTION" >SDL_SetPalette</TT ></A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlcolor.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlpixelformat.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_Color</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="video.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_PixelFormat</TD ></TR ></TABLE ></DIV ></BODY ></HTML >